Northfield Underpass

[urbanfox]

I'm a member of a group on Facebook for people to post old photos of the area on. Two have been posted this evening which are very interesting though...

They seem to be taken around the time the A38 bypass of Northfield was being built, they show the central reserve of the B4121 Bell Hill from here onwards excavated, revealing what appears to be a tunnel entrance, complete with walls. For one, it might explain the unusual shape of the carriageways at the top end of Bell Hill. But it's opened up plenty of other questions!

Nobody who has commented seems to know for certain where it would've gone - but with one person suggesting Great Stone Road and another near the library - somewhere near the junction of Great Stone Road and Church Road seems likely, which to me seems rather pointless - unless it was part of a bigger scheme? Perhaps the dual carriageway would've continued on? Down Church Hill and along West Heath Rd and out to the A441 and M42?
Could it refer to near where Great Stone Road and the A38 - providing a tunnelled bypass of the High Street? In any case, it seems they built the entrance and that was about as far as they got.

Have had a quick mooch around, but unfortunately not been able to find anything too useful other than a bit of speculation - I know you guys are an absolute goldmine for this sort of stuff, so would love to see if anyone here knows any more about this and knows exactly what the plan was?

[Truvelo]

The best I can do is this from the 1950s. The second map shows the planned grade separations for the city but it would appear Northfield is at-grade.

[urbanfox]

Aww, if anyone was going to know the ins and outs it was going to be you!

The top map seems to show the A38 on a similar line to where the recent bypass sits, so perhaps it was thought they might grade separate it. But then why would the B4121 would get an underpass when the A38 is clearly the major player at the junction, unless they were thinking of something rather larger, similar to the A34/A453 in Perry Barr with a flyover for the A38 and underpass for B4121.

Also interesting how the second map shows all sorts of grade separations that never happened, but nothing at all along the A34 which has 2 miles of grade separation.

Out of interest, where do you find all the old maps and plans from?

[Truvelo]

The maps are at Kew. They are a little early for what we're looking for. Similar maps from the 1960s would be better. There was a flyover planned at Six Ways in Erdington which this map doesn't show, nor similar treatment for the A41/A4040 junction in Handsworth.

My guess is the earthworks at Northfield were built with futureproofing in mind so the final layout of the junction must have been known. Now finding it has proved an impossible task. There is a bit of text accompanying the map.

[Chris Bertram]

There is a bit of text accompanying the map.

Well, that describes Herbert Austin Way to a T - except that the Travellers' Rest has gone, and instead of a "large gyratory island", we have a forest of traffic lights.

[Bryn666]

The A38 might be the "main" road but I can imagine the thinking being taking traffic up to the west and straight onto the A4123.

It'd be a very effective bypass corridor and an M5 relief.

[ais523]

I'm a member of a group on Facebook for people to post old photos of the area on. Two have been posted this evening which are very interesting though...

They seem to be taken around the time the A38 bypass of Northfield was being built, they show the central reserve of the B4121 Bell Hill from here onwards excavated, revealing what appears to be a tunnel entrance, complete with walls. For one, it might explain the unusual shape of the carriageways at the top end of Bell Hill. But it's opened up plenty of other questions!

I went down that road most days for years, before the bypass was built. The tunnel entrance was actually more dramatic than in that photo; it was 100% a pre-built tunnel/underpass entrance, and couldn't reasonably have been anything else. (There's since been a lot of soil added in the area, but one tree, which nowadays barely reaches the surface because (despite being pretty tall) it starts growing so far below current ground level, gives evidence of its previous depth.)

However, even at the time I recall thinking that there was nowhere obvious for it to connect. The options are:

• "Straight on" on the B4121: there's room for this (just about), but it doesn't seem like a movement that would need or benefit from grade separation. (Nowadays that stretch of the B4121 has a 20 limit, which is clearly too slow, and Great Stone Road is the only plausible alternative and goes quite some distance out of the way if you're looking to go north.) To put it in perspective, the traffic lights at the B4121/Great Stone Road junction have currently failed, and neither the traffic nor pedestrians seem to have any problems with the resulting inconsistently signalised junction; traffic levels are just too low (although queues do form at the junction; they aren't completely minimal). So this seems like an unlikely use of resources.
• Right onto the then-A38 towards Rubery. This was my first thought upon coming to this thread; it's a sufficiently major road, after all. I was going to say "but there's nowhere for it to connect, Northfield town centre is packed", but then I realised that a stretch of the former A38 through Northfield town centre (from the restaurants to the Post Office) has the shops on one side taken a surprisingly long distance away from the road; the pavement is actually considerably wider than the road in that section, and although other shops have been built since, they're shed-type things that could presumably easily be bought out. On the other side, although not in quite the same place, is (and has been for ages) a small car park that could presumably be occupying land until a junction could be built there. In fact, looking at a satellite picture to get a better perspective of things, even the shops that aren't conspicuously far from the road are further apart near the junction; you could fit a D2, or maybe even a cramped S6, in there with room to spare. So even though it feels like there's no room to build an underpass, there totally is. (Not as much room as on the B4121 side, but perhaps enough, or perhaps it was once more.)
  
  The other problem is, who'd use such a connection? Of course, we have to assume that the Northfield Bypass doesn't exist, but the main strategic use of such a junction would be for traffic coming from the motorways around the south of Birmingham in the direction of Wolverhampton, and in such a case, I don't see why you wouldn't just use the M5 (given that to even get to Northfield from the motorways to the south, either you use primary routes and go past Lydiate Ash and can join the M5 there, or you use B roads and come up the B4121, and cross the A38 at Northfield). Perhaps it was intended for traffic coming from the M40 direction (but checking journies like Oxford to Wolverhampton in direction-finding programs gives me routes along the M6 and even M6 Toll in preference to anything that goes near Northfield).
• Left onto the A38 towards Birmingham. When I started writing this post, this was my top idea. There is plenty of room to make a connection/build an underpass; there is (and always was) a filter lane (now part of the A38) for the movement that goes the other way round Northfield shops (showing that the movement was considered important enough to not go through Northfield town centre); and the A4123 was intended to be a new major road from Birmingham to Wolverhampton, so it makes sense that it has good connections at the Birmingham end. The shape of the Bell Lane spur (that's currently used just to access houses) makes me suspicious about the plans for the junction, in that the parallel spur + filter lane combination looks a lot like the junction was planned to be bigger than it is (at the time, with the bypass nonexistent, you could have made space to make the filter lane free-flow with a proper merge onto the A38).
  
  The big problem with this plan is that it's just such a circuitous route. However, it's not as bad as I thought. I tried a few routes that might want to go this way (Bournville to Wolverhampton is a good one), and although it's slower, it's only marginally so (2 minutes slower), and being held up by lights in Northfield is half the reason for that. Still, an approximate 135-degree turn isn't really what you'd want to put on your strategic routes, because so many people will rat-run and cut the corner (in this case, by using Whitehill Lane, which I would definitely describe as "not suitable for HGVs" because it's so hilly, but which was (and probably still is) nonetheless a commonly used rat-run for vehicles that can make it). So I fear that an underpass in this direction might not get the users it planned. And besides, the filter lane setup there was (and is) a higher quality of junction than is typically expected in the area, and so might be less in need of upgrading.

Having looked through the reasoning, both the connections onto the former A38 seem to make some amount of sense as an underpass destination. I think the connection south towards Rubery is probably the correct explanation, though, if only because there seems to be evidence on the ground in Northfield town centre.

[Benny]

Bournville to Wolverhampton is a good one

My Dad used to live in Bournville and he bought his SEAT from Wolverhampton

What I'm going to do is have a chat with my Step-grandfather, he is 90 years old and a retired architect having lived in this area all his life he may have some idea what it was about. If I find anything out I'll report back!

[Truvelo]

My assumption has been something like this with the A38 diverted north of Whitehill Lane. I can't see Shenley Lane being important enough to justify having a tunnel portal.

[urbanfox]

I'd certainly go along with the idea of a tunnelled bypass of the High Street and I also find it odd that it should have a portal on Bell Hill, I don't see why the A38 would need to be diverted from its original course though.

The obvious answer to that is so that it links up with the tunnel, but I'm sure space could easily have been found along the A38 for a portal.

Maybe they just dualled it around the same time they were sticking tunnels and flyovers elsewhere around the city and thought 'Why not? We might find a use for this one day'!

[ais523]

My assumption has been something like this with the A38 diverted north of Whitehill Lane. I can't see Shenley Lane being important enough to justify having a tunnel portal.

That picture doesn't work, for a reason unclear from the aerial photo. You took the A38 right over a very steep hill. (I also think it's unlikely that the A38 would be diverted on other grounds; its current alignment seems entirely reasonable.)

I also think it's unlikely that there were plans to dig a tunnel all the way under Northfield (I prefer the layouts where the underpass was just intended for grade separation of the junction). If you did, though, the most sensible place for it to come out would be somewhere around South Road (further south than Truvelo has it); there's enough room there, and a steep enough hill that the tunnel and slip roads would fall into place naturally. (However, I haven't seen any evidence of a tunnel portal or plans for one on that side of Northfield; I can take a look later if people like, but I'm not expecting to see any flared sliproads or houses moved back from the road or the other typical signs that indicate a grade separation was planned.)

[ais523]

This is still bothering me, and because the Internet doesn't seem to know, I've taken to looking up sources in the local libraries.

My current theory is that this wasn't actually intended as an underpass, mostly because the timings all seem to be off. Apparently the terrain in this area has been historically awful, and it looks like the most plausible theory is that the west carriageway (which definitely came first) was built on the easiest-to-build route (explaining the shape), and that the east carriageway was built to a more direct route to access local houses. (If you look at the pavement on the east side of Bell Hill near the junction with Whitehill Lane, e.g. from this Street View image, you can see something that's constructed roughly like a subway entrance but doesn't go deep enough. This has been here for years, and I think it's evidence that the east carriageway had to be built partially in mid-air in order to keep the elevations reasonable.

So in other words, this looks a huge amount like an underpass entrance (and used to be even more so), but it may just have been a case of building two carriageways at separate times in the most reasonable way. Still, I'd rather like to check further sources.

In order to help narrow my search, does anyone have information on when Bell Hill was dualled? The second carriageway appears on the Seventh Series map (1955-1960) and on the "1:25000" map (which doesn't appear to have a date). The New Popular map appears to be broken in the area. The Popular map (1920-1939) probably doesn't show it (although it's hard to tell). Most of SABRE's other maps aren't at a scale that would show the carriageway. (It doesn't help that the area in question was basically rural until the 20th century, meaning that it doesn't show up in most history books.) 1920-1960 is far too big a range to get useful information, so I'm hoping that someone here might be able to narrow the range down a bit.

EDIT: Narrowed it by one year; the specific Popular map that SABRE has of Northfield dates from 1921. Not really that helpful, though :-)

EDIT: And got a date for the recent end, too: 1953. Again, still too large a range to be useful, but we're making progress!

[Truvelo]

I've been looking at Old-maps and there's a cutting on the west carriageway just north of Bell Lane which was there before the second carriageway was added. There's also aerial imagery from 1945 showing the current layout of the road but suggesting the new carriageway is a service road serving the houses.

I agree with your theory about the dualling being to straighten the road rather than as part of an underpass. The idea of GSJs wouldn't have occurred in the 1920s. There are numerous examples of dualling in Birmingham where one carriageway is the existing road and the other takes a straighter line.

[ais523]

Ooh, that photo you refer to pretty much nails it. You wouldn't build half an underpass, then wait for years to build the other half.

My research indicated that the roads in question used to be highly dangerous (lethal in some cases) due to the terrain. Bristol Road apparently had a different alignment back when Bell Hill became widely used (my research didn't indicate what, but the obvious guess is that it went along Bell Lane, which implies that the A38 is now following the historical path of Bristol Road once it deviates from the modern path). Both were originally turnpike roads, and typically badly maintained ones at that (and Bell Hill genuinely was equal to Bell Holloway; hard to believe that nowadays given how different the roads are today). Presumably at some point there was a modernization effort which lead to the roads being surfaced and made less hilly, which would give us our west Bell Hill carriageway, and the east one came about rather later when the area became urban (Northfield pretty much stopped north-west of the Bell Inn for quite some time).

[Truvelo]

The original turnpike era route is easy to make out, especially on older maps. This is how it would have looked. There may have been other deviations from the current route, for example where Tessall Lane crosses Bristol Road although it's hard to see where an earlier route would have went.

It seems tracking down the route of the turnpike is a lot easier than trying to find something from the 1960s.

[PhilC]

I read the Most Optimistic Future Proofing thread and thought of the Northfield underpass. Searching for information I stumbled across this thread. Although it's several years since this thread was last updated I thought I'd share my rather scant memories. It might be the missing piece of the jigsaw.

In the 1950s my grandfather used to live in Hoggs Lane. When we visited him we used to cross the Bristol Road into Bell Lane and then turn sharp left into Ulwine Drive and then right into Vineyard Road. Neither of these roads is shown on the OS map upthread. I know that these roads were built between 1954 and 1957.

I can remember being driven down Bell Hill and along Shenley Lane a couple of times before it was dualled. It was a narrow country lane with just the odd street lamp until it reached the top of Barnes Hill, which has been dual carriageway for as long as I can remember. This must have been some time after 1957. The whole length was certainly dualled by 1966. This would narrow the date down to a 9 year window.

I remember the underpass portal being there and always assumed it would bypass Northfield by following the line of the current bypass to emerge somewhere by the Frankley Beeches Road junction. There was open land behind the shops which was used as a car park for years.

Looking at the OS map upthread the second road shown parallel to Bell Hill is almost certainly a service road to the houses. Old OS maps only showed dual carriageways on classified roads. Yellow roads showed the width, less than 14 feet or over 14 feet. Interestingly, the map shows both Bell Hill and Bell Holloway as wider than 14 feet. From my memory both these roads were very narrow, and Bell Holloway still is to this day.

[ais523]

Some possible additional information: this thread talks about some plans for south Birmingham in 1967. At this point in time, the B4121 north from Northfield existed but wasn't classified, and was planned for an upgrade; and the A38 Northfield Bypass didn't exist, but was planned.

Of course, both actually happened, and the building of that B4121 section happened well before the corresponding A38 section. But there were plans to build both, and it wouldn't surprise me if those plans were synchronized with each other.

As such, perhaps the "tunnel portal" here was a real tunnel portal, and was intended to connect to the planned section of A38 to the south? This would explain why it was never completed; the B4121 was apparently intended to be a major strategic road (explaining why it was built as D2 despite the traffic levels apparently not justifying that), so would probably warrant a freeflow connection to the A38 to the south. The basic idea would have been to take traffic aiming for Harborne off the A38, and give a route for traffic aiming for Quinton, when starting from south Birmingham; at the time there would have been no real alternatives. (The B4121 still does this job even today; it simply doesn't get as much traffic as the traffic modellers might have expected.)

Of course, by the time the Northfield bypass was finally completed, it had become clear that the B4121 wasn't, as initially expected, a major strategic route, and the tunnel portal could be filled in. (That said, the current A38/B4121 junction, which is a complex design involving several traffic-light-controlled flat crossings, does get congested sometimes, or at least did before the lockdown started. So perhaps there was a point to the future-proofing after all.)

[Truvelo]

The A38 might be the "main" road but I can imagine the thinking being taking traffic up to the west and straight onto the A4123.

It'd be a very effective bypass corridor and an M5 relief.

I'm beginning to think this may now have been the plan. In the thread ais523 linked to the 1967 map shows the Northfield Bypass along with the continuation up the B4121. That map also shows part of the Edgbaston Expressway. It's possible there was an intention to divert the A38 up the A4121 and along the Edgbaston Expressway to rejoin the existing A38 near Bristol Street/Lee Bank Middleway.

[ais523]

Another relevant thread: this old SABRE thread from 2002.

A commenter at the time was sure that the portal was built to allow a connection between the B4121 to/from the west, and a hypothetical Northfield bypass to/from the south, claiming to have seen evidence in a local highways programme.

It references this thread, but most of the comments there are speculation; it's unclear who if anyone was talking from actual knowledge of the plans.